Abstract B113: Unique hormone receptor signatures of inflammatory breast cancer in a cohort of Puerto Rican women

Abstract

Inflammatory breast cancer (IBC) is an uncommon although highly lethal form of breast cancer. Existing IBC research focuses mainly on United States or European populations, limiting current knowledge of patient profiles in Hispanic populations. Given the unique genetic admixture that exists in PR, we are interested in characterizing IBC within this population to broaden understanding of this disease. We designed a retrospective study which was deemed exempt by the UCC-IRB. A sample of breast cancer patient charts were reviewed at Manatí Medical Center and Pavia Hospital. Of these, 18 eligible subjects with a new primary diagnosis of IBC between 2012-2019 were identified and data was collected from oncologist and pathologist reports. On review, 78% of patients were negative for HER-2/neu receptor overexpression and there was a difference, although not statistically significant (p=0.09) compared to other receptor status. This result differs from other studied populations which place HER-2/neu positivity in the range of 36-60% for IBC. Interestingly, 36.4% expressed the particular signature (ER+, PR+, HER2/neu-) and 36.4% presented as triple negative for tumor markers (ER-, PR-, HER-2/neu-) on pathology review. Our data suggests that within the context of the population studied, IBC is less likely to express HER-2/neu receptor compared to IBC in other populations, and we identified two specific signatures that comprise the majority of the cases studied. To improve patient outcomes for IBC it is critical to have foundational understanding of the disease characteristics and course within a diverse group of patients. This study aims to set such a foundation within the population of PR. With this knowledge, further treatments can be tailored to meet the needs of unique or minority populations such as this one. Citation Format: Zoe C Underill, Mayra Rivera, Michelle M Martinez. Unique hormone receptor signatures of inflammatory breast cancer in a cohort of Puerto Rican women [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B113.